You will be amazed how many web
designers and dubious Search Engine Consultants use wrong practices in web
design and Search Engine Optimization.

There are two reasons for this:

Deliberately, to manipulate the search engines for better rankings.

Unintentional, due to lack of knowledge, time, control or other
reasons.

Learn
from other's errors

(there is no shame to make an error, there is only shame if you don't
learn from it)

For the second
group, you are here at the right place. I have compiled a top list
(still growing) of most used web design mistakes and
most used
wrong SEO techniques.
Learn how to
avoid web design mistakes and how to identify (and avoid) unethical SEO
techniques.
Use this
information as
a checklist or guideline for your website's design and your optimization
methods. If
you recognize any of the mentioned practices, then get rid it of ASAP!

Do a regular health check

Like your car,
your website needs to have a check up now and then. Especially when you
have your website for a longtime and have a high activity of changing
and growing content. A change in your site's architecture, lay-out or
content can
result in destructive (ranking) results which immediately will have
effect on your ROI.
Especially
checking your outbound links is a very important issue. If one of
your outbound links is linking to a spammy site, then your site can be
infected too by some filter.

Do the same for
your SEO. The algorithms of search engines changes a lot. Also the
guidelines of proper web design, proper SEO and proper link building changes now and then
Keep yourself
informed and check your own methods regular and be convinced that they
are still valid. The best tool
to check your website's performance is analyzing your website
statistics.

Your statistics tells you how your pages are performing and if visitors
use the right keywords to find your site. Your statistics also tells you
your conversions, especially when you use specific SEM campaigns. Many
people think that SE ranking is the most important critical factor of
your website's success. Wrong, it is your ROI which should be your most
important critical factor. And your website statistics can tell you how
your site is performing.

What works
today can fail tomorrow.

What happens when using bad
design and SEO manipulation

Errors and an
overflow of HTML warnings can hurt the accessibility and usability of your site for as
well human beings as crawlers.

Slow loading
pages can cause premature bouncing

Visitors can get
lost in your site when using wrong navigation

Visitors will
point quickly at the white cross in the red square

Search engines
can 'filter' your site (lower ranking)

Search engines
can ban your site (not ranking at all)

Your site can
land in bad neighborhoods (bad linking)

Visitors hate pop
ups (and will bounce away)

You have to pay a
lot for ads while you could be in the organic SERP

You can get
negative feedback from your visitors/customers

You can get
serious complaints (even from search engines)

The existence of
your site has no added value in the www (bad, poor content)